What is the Urban Waterways Restoration Study?
The Urban Waterways Restoration Study (Study) will identify and prioritize cost-effective plans to restore the habitat and ecosystem as well as reduce the flood risk along critical reaches of the South Platte River from 6th Avenue to 58th Avenue, as well as sections of Harvard Gulch, and Weir Gulch. This study is a collaborative effort that is sponsored by the United States Army Corps of Engineers (USACE), City and County of Denver (CCD), Urban Drainage and Flood Control District (UDFCD), Colorado Water Conservation Board (CWCB) and The Greenway Foundation.
How did this study come about?
In 2000, Congress provided approval for U.S. Army Corps of Engineers to study ecosystem and flood risk issues along the South Platte River in Arapahoe and Adams Counties. Congress added Denver County to the study authorization in 2008, and we began the Reconnaissance Study which is required prior to beginning a feasibility study with the USACE. This study was completed by the USACE with CCD in 2010. The results of the 2010 study indicated federal interest in pursuing a Feasibility Study with CCD as the cost-share sponsor.
It is part of the USACE mission to protect and restore the nation’s environment and major waterways.
Why is the study necessary?
Urban growth in Denver which has reduced natural vegetation to promote habitat has negatively impacted the ecosystem surrounding the South Platte River and its tributaries, specifically Harvard Gulch and Weir Gulch. Migratory birds protected under the Migratory Bird Treaty Act and other species rely on riparian corridors and wetland habitat, both of which have been lost with the channelization of these waterways and increased development.
The study’s purpose is to identify potential improvements that could reduce the flood risk to numerous structures that are located in high flood-risk areas in the Harvard Gulch and Weir Gulch watersheds. The study will be looking at alternative alignments that will use existing public property wherever possible in order to minimize private property acquisition.
How long has the Study been underway?
The Reconnaissance Study, which determined federal interest in conducting a more detailed Feasibility Study, was completed in 2010. The City and County of Denver signed a Feasibility Cost Share Agreement (FCSA) with the Corps in May 2014, and the Feasibility Study began shortly thereafter. Since the signing of the FCSA, the U.S. Army Corps of Engineers and the sponsor have been conducting analysis on the existing conditions of the study area.
How much will the Study cost?
The total study cost is $3 million and is being cost-shared with a 50:50 split between U.S. Army Corps of Engineers and City and County of Denver.
Where is Weir Gulch and Harvard Gulch located?
Weir Gulch flows into the west-central part of the City and County of Denver, entering the City near West Center Drive and South Sheridan Boulevard. It flows through the Westwood, Barnum and Barnum West, Villa Park and Sun Valley neighborhoods where it connects to the South Platte River. In some locations it is an open channel, while in other locations it is in a concrete channel or even underground in pipes.
Harvard Gulch is in south-central Denver. It is an open channel at South Jackson Street north of East Yale Avenue flowing west through the University Park, University, and Rosedale neighborhoods. In many locations it is an open channel although it is within a concrete channel between South Race Street and South Downing Street where it is conveyed underground for a few blocks, reemerging as an open channel from South Ogden Street to South Logan Street. At South Logan Street, it flows in to a large storm drain culvert which carries the runoff underground through the Overland neighborhood to the South Platte River at Grant Frontier Park.
Why is the City investing in this Study?
The intensity and duration of rainfall can vary considerably along the Front Range during a rainfall event. Intense periods of rainfall can be localized, and cause significant flooding in one area, and leave other areas relatively untouched. For example, the significant flooding in September 2013 in Aurora, Commerce City, Boulder, Lyons and Longmont occurred in historic neighborhoods that hadn't seen flooding in anyone's memory, while much of Denver only received heavy rainfall. If rainfall patterns had been slightly different, flooding could have occurred within the study areas.
What is the timeline for the Study?
The Feasibility Study review and approval process will take 4-5 years to complete. The Study began in May 2014 and will be complete by approximately the end of 2018.
Public input was received during the initial scoping period in Spring of 2015. USACE and the City and County of Denver developed a variety of conceptual solutions (also called alternative plans) during the Summer and Fall of 2015. Additional public input on the conceptual alternative plans was gathered in Jan/Feb of 2016.
USACE is currently evaluating and comparing the alternative plans based on several factors, including the benefits and costs of each waterway. Once that analysis is complete, a draft feasibility report will be released to the public for review in the Spring of 2017.
After the public and agency comment period on the draft report, all comments received will be considered, and a final feasibility report will be completed near the end of 2018. If the feasibility study is approved, a Chief of Engineers’ Report will be completed and transmitted to Congress for authorization in 2019.
What happens after the Study?
After the completion of the Chief of Engineers’ Report in 2019, the project sponsors will then begin to seek funding for the design and construction of improvements based on the recommended plan.
The costs to solve the issues are significant and could take many years to fully implement.
Why is the Study being done now?
The original studies on these waterways were prepared over two decades ago and focused solely on flood control. Since that time, there has been growing concern for the ecological health of urban rivers and streams and the Feasibility Study process will address this. In addition to evaluating these waterways in the interest of reducing flood risks, goals of the study include protecting critical water supplies, improving water quality, and restoring ecosystem habitats. These are important considerations in identifying potential improvements in each of the waterways.
Because of improved modeling capabilities, the accuracy of data (like topography) availability, and a heightened awareness of ecosystem health, the Study sponsors are conducting a series of studies to reassess the condition of these waterways considering both ecosystem health and flood risk management.
What input is the City getting since the last public meetings on Weir and Harvard Gulches?
Thank you to those who have taken the time to comment. They are helpful in the alternatives evaluation and to know what you like and don’t like about our process.
One of the main subjects is comments from Harvard Gulch property owners about potential impacts to their properties. After speaking to several owners we have become aware that review of the Integration Plan materials from the August 2016 meeting is leaving some with the perception that the impact to properties is known at this time. As a result, the web materials are being modified and additional FAQ’s are being added so that the perception does not continue to propagate in the community. It is our goal to be transparent through this process.
The second significant item involves issues resulting from a greater awareness of the floodplain. We continue to receive questions about building permitting, buying and selling homes, impacts to property values, etc. all relating to the existing floodplain and any future changes. The City attempted to answer many of these questions in the meetings earlier this year, but as the public becomes more informed the level of interest and number of questions is increasing. The City is working to revise its website with more general floodplain information to help answer many of these questions. This information will be general in nature and is intended to help answer questions surrounding the floodplain and not the Urban Waterways Study. We anticipate adding information over the next 6-8 weeks.
Please consult with your real estate agent or insurance agent if you have questions about your property. The City can provide data and facts to help our citizens make informed decisions.
Why are outside agencies sponsors of this Study?
State and federal agencies are involved in, and are providing technical and financial assistance for the Feasibility Study because they also have significant interests in maintaining the ecosystem health of the country’s rivers and streams, and in mitigating flooding hazards.
What is the UDFCD, and what is their role in the Study?
The Urban Drainage and Flood Control District works with local governments to address multi-jurisdictional drainage and flood control challenges to protect people, property, and the environment. Their mission not only includes identifying and mitigating flood risk; but protecting and enhancing the ecological health of urban rivers and streams, improving water quality, and enhancing wildlife habitat.
What is CWCB and what is their role in the Study?
The Colorado Water Conservation Board (CWCB) is part of the Colorado Department of Natural Resources. Their responsibilities include protecting Colorado’s streams, flood mitigation, watershed protection and stream restoration, as well as other water related issues. The Board, through its Water Supply Reserve Account, awarded $450,000 to The Greenway Foundation for this Study.
"It's an important component of Colorado's water plan we're working on — to have a healthy watershed and walkable and bikeable parts of the city that have a waterfront," said James Eklund, director of the Colorado Water Conservation Board.
I've lived along these waterways for several decades and have never seen a significant flood. Why is the City investing in this?
The South Platte River, Harvard Gulch and Weir Gulch waterways were identified as having the greatest need for ecosystem restoration and flood risk management that fit within the budget of the study. As part of the Urban Waterways Restoration Study efforts, we will evaluate the floodplains and flood risks within the study area. Newer and better information and hydraulic models will be used in this evaluation. The goal is to develop the best and most accurate information we can to better define and evaluate plans to reduce the flood risks, while providing important recreational and ecological benefits.
What is the hundred-year (100-year) floodplain and why is it so important?
A 100-year flood is a flood event that has a 1% chance of occurring in any given year and is the national standard for identifying areas of significant flood risk along major rivers, streams and gulches. The 100-year flood is also referred to as the "1% annual chance flood" or "base flood." The 100-year flood is generally expressed as a flow rate. Based on the expected 100-year flood flow rate in a given creek, river or surface water system, the flood water level can be mapped as an area of inundation. The resulting area is referred to as the 100-year floodplain, which is an important factor in building permits, environmental regulations, and flood insurance. It's important to understand that not all locations within the 100-year floodplain have the same chance of flooding. For example, areas of lower ground (usually closer to the gulch) have a greater than 1% chance of flooding because smaller floods can inundate those areas. Conversely, areas outside of the 100-year floodplain get inundated by larger (less than 1% chance) flood events.
How will I know if I'm in the floodplain?
The 100-year and 500-year floodplains have been mapped for most of Denver's major rivers and streams by the Urban Drainage and Flood Control District (UDFCD) and then adopted by FEMA. All properties within the mapped 100-year floodplain limits are notified once a year by the UDFCD via mailed brochures. Floodplain information is available through the City & County of Denver website at https://www.denvergov.org/maps/map/floodplain, the UDFCD website at http://udfcd.org/mapping, or by contacting the City & County of Denver's Floodplain Management Group at email@example.com or 720-865-3215.
Is my property in the floodplain if I received a letter notifying me of this Urban Waterways Restoration study?
Not necessarily. You've received notice of the studies because you live or own property in the general vicinity of the South Platte River, Weir Gulch or Harvard Gulch study area. Verification of whether your property is in a floodplain or not should be obtained by visiting the City & County of Denver online floodplain map at https://www.denvergov.org/maps/map/floodplain, or by contacting the City & County of Denver's Floodplain Management Group at firstname.lastname@example.org or 720-865-3215.
What happens next with the Study?
Meetings were held for Harvard and Weir Gulches in August 2016. At those meetings the USACE indicated that the Draft Feasibility Study would be ready to release in late 2016. The schedule has now changed to Spring of 2017. The Draft Feasibility Study will indicate the preferred alternatives that are eligible to move forward in the feasibility study phase. The public will have the opportunity to comment, and document their support and concerns over a period of 45 days. Additionally, the USACE is planning on hosting a public meeting during this 45-day review period. The report will be available for review through the USACE standard process and through the study’s website at https://www.denvergov.org/denverwaterways. Anyone signed up through the website will get an email notification of when this report is available for public review. If you would like to receive updates on the study, please visit the study’s website and click on the “Sign Up for Updates” button.
Is my property going to be impacted?
There is no way to definitively answer this question until a project’s detailed design is well underway. This feasibility study is only a first step in a very long process.
As a part of the study, alternatives that are being discussed include those that were presented at the public meetings in Jan/Feb of 2016. As an example, potential flood risk reduction infrastructure improvements can be underground pipes, channels, detention ponds, or elevate structures to minimize flood risk. Each of these alternatives has a differing need for space. Some conceptually fit into the existing City owned property, and some do not.
The intent of the Feasibility Study is to demonstrate whether a feasible solution exists that meets criteria for federal funding eligibility. If the project is ultimately funded, the concept plan will be a starting place for future design work. In all likelihood the final infrastructure design will vary substantially from the concept plan along with the potential property impacts.
How are improvements going to be paid for?
Recommendations of the Study will identify potential costs for future improvements and specific projects to be implemented. This will enable the Study sponsors to then identify possible funding sources for future projects. Recommended projects could be eligible for up to 65% Federal cost sharing through the USACE depending on the specifics of the projects.
How much money is available now?
The City’s 50 percent share of the $3 million study funding is secured. The Federal government’s 50 percent share was secured for fiscal years 2014, 2015, and 2016. The federal share for fiscal years 2017 will be pursued through the normal Federal budgeting and appropriations process.
When can we expect to see construction?
The Study will be completed in late 2019. Funding for design and construction implementation will occur sometime after the study is complete, but it is impossible to predict an exact time frame. A continued public engagement process is planned for future design and construction implementation phases.
How do I get more information?
The public process for the Urban Waterways Restoration Study began with a series of three public meetings, one near each of the study areas, to inform the public about the study, answer questions, and receive initial input.
A second series of public meetings took place in early 2016 to review alternative plans for each of the study areas and to collect public feedback on the recommendations. A meeting in late spring of 2017 will seek public input on the draft recommendations for all three study areas.
The web site for this Feasibility Study is www.denvergov.org/denverwaterways. The web site is a good source of background and updated information as well as an ongoing opportunity for public input for those who cannot attend the public meetings or prefer to provide input electronically.
How can I give input on the Study?
You can attend the public meetings and also visit the website to provide comments and feedback and sign up to get updated study information and: www.denvergov.org/denverwaterways